What determines if an area in the "map" section of a species page is orange or green?

[thomaseverest]

Welcome to the forum! This has been asked several times before, and you can probably find your answer elsewhere. Such as:
https://forum.inaturalist.org/t/map-legend-what-does-the-orange-color-represent/3573
https://forum.inaturalist.org/t/colors-coding-on-maps/13795/4